1. Field of the Invention
This invention relates to a construction of a door glass guide, and particularly to improvements in a construction of a door glass guide provided in a door frame of a motor vehicle's door with the door frame.
2. Description of the Prior Art
As shown in FIGS. 16 through 19, a construction of a door glass guide in a motor vehicle with a door frame is normally of such arrangement that a door glass run 3 being a generally U-shape in cross section is provided in a guide portion 2 of a door frame 1, whereby the door glass run 3 guides the front or rear end edge of a door glass 4 and restrains the same in a direction of thickness of the door glass 4.
Here, the door glass run 3 is provided with an outer lip 3A and an inner lip 3B, both of which are obliquely extending from the forward end portion of the U-shaped section toward the center of the section. The outer lip 3A and the inner lip 3B are brought into sliding contact with the inner and outer surfaces of the front or rear end edge 4A of the door glass 4, so as to guide the door glass 4 in the opening or closing direction.
The outer lip 3A and the inner lip 3B are elastically deformable within a predetermined range in the direction of the thickness of the door glass 4.
In consequence, if an outwardly pushing force acts on the door glass 4 for example, then the door glass 4 outwardly pushes the outer lip 3A to deform the same, as shown in FIG. 20.
Now, when the motor vehicle runs at high speed, air flows along the side surfaces of a vehicle body become high, whereby the outside R2 of a vehicle compartment is lower in pressure than inside R1 of the compartment as indicated in FIG. 19, so that such a phenomenon occurs that the door glasses 4 are sucked outwardly from the vehicle body.
In consequence, in the motor vehicle equipped with the door having the door frame 1, if the door glass 4 is to be raised or lowered during the running of the motor vehicle at high speed, then the door glass 4 is sucked outwardly from the vehicle body as indicated by hypothetical lines in FIG. 19. As the result, an upper side edge 4B and an oblique edge 4C of the door glass 4 move outwardly from the vehicle body, thus presenting such a disadvantage that both edges 4B and 4C as shown in FIG. 16, do not run smoothly into the door glass run 3 coupled into an upper side portion 1B and an oblique side portion 1C of the door frame 1.
The reason is that, in the conventional door glass run 3, there are gaps 5 formed between the inner lip 3B and a base portion 3C of the door glass run 3 and between the outer lip 3A and the base portion 3C of the door glass run 3, whereby, when a force sucking outwardly from the vehicle body acts on the door glass 4 during the running of the motor vehicle at high speed, both lips 3B of 3A each as shown in FIG. 17, have a deflection by a value of one of the gaps 5, so that the door glass 4 easily moves outwardly from the vehicle body.
Now, the cross-sectional shape of a door glass of a side door in a motor vehicle, particularly a passenger car, is normally a circularly arcuate shape, and a sliding path 4D of the door glass 4 has a circularly accuate shape as shown in FIG. 21 for example. In contrast thereto, a plane of rotation 6 of an arm, not shown, of a window regulator for raising or lowering the door glass 4 is a plane in the substantially vertical direction.
From the relationship between the sliding path 4D of the door glass 4 and the plane of rotation 6 of the arm of the window regulator as described above, in order to operate the window regulator smoothly, such an arrangement is adopted that, normally, at the central portion of a door body 7A of the door 7, the plane of rotation 6 of the window regulator is disposed inwardly in the widthwise direction of the vehicle body with respect to the sliding path 4D of the door glass 4 downwardly of a beltline 8 in the door 7, and, at the top and bottom portions of the door body 7A, the sliding path 4D of the door glass 4 is disposed inwardly in the widthwise direction of the vehicle body with respect to the plane of rotation 6 of the window regulator.
However, if the plane of rotation 6 of the window regulator and the sliding path 4D of the door glass 4 are arranged in the above-described positional relationship, then, when the door glass 4 is fully closed, the bottom portion of the door glass 4 is pushed outwardly in the proximity of the beltline 8.
More particularly, in the proximity of the beltline 8, the door glass 4 urges the outer lip 3A of the door glass run 3 against the outer surface portion 1A of the door frame 11 to deform the outer lip 3A as shown in FIG. 20.
The state of the door glass 4 in this case is indicated by a two-dot chain line 4E in FIG. 21.
When the door glass 4 is pushed outwardly by the window regulator when the door glass 4 is fully closed as described above, the contact pressure of the door frame 1 with either the outer lip 3A or the inner lip 3B is varied in the vertical direction of the door frame 1, thus presenting the disadvantage that the sealing performance of the door glass run 3 is lowered thereby.
Furthermore, in a motor vehicle of the type in which the radius of the circular area of the section of the door glass 4 is small, the outer surface of the door glass 4 may be bulged outwardly from the outer surface of the door frame 1 in some cases, thereby presenting the disadvantages that the appearance of the vehicle is deteriorated and the characteristics of aerodynamics is lowered during the running of the motor vehicle at high speed.
This trend is notable with a motor vehicle of a so-called flush surface type, in which the difference is small between the outer surfaces of the door frame 1 and the door glass 4.
Even when the door glass is displaced in the direction of the thickness thereof as described above and the forward end of the door glass is shifted from the center of the door glass run in the state immediately before the full closing of the door glass, as the means for introducing the forward end to the center of the door glass run, for example, there is a construction wherein the proximal end portion of the lip, to which the door glass is shifted, is obliquely extended and reinforced by an insert, as disclosed in West German DE 3106909A1, and another construction wherein the proximal end portion of the lip, to which the door glass is shifted, is formed of a hard material and extended obliquely, as disclosed in Japanese Patent Kokai (Laid-Open) No. 164420/83.
Furthermore, as the means for controlling a deformation value of the lip, for example, a portion of the side wall of the main body of a door glass run positioned on the rear surface of the lip of the door glass run is bulged in the direction of the thickness thereof and this bulged-out portion is caused to interfere with the rear surface of the lip so as to restrict the maximum displacement value of the lip, as disclosed in Japanese Utility Model Kokai (Laid-Open) No. 122366/84.
All of the above-described prior art require that the whole or a part of the construction of the door glass run have a sectional shape different from one in the ordinary construction of the door glass run, thus presenting the disadvantages from the viewpoints of the assembling to the door frame and the manufacturing cost.
To obviate the above-described disadvantages, applicant proposes a door construction in a motor vehicle, wherein a spacer is interposed in the rear of a lip of the door glass run, whereby the lip is not pushed outwardly in the widthwise direction thereof and deformed by the door glass.
In the above-described door construction of the motor vehicle, the aforesaid spacer is only elastically coupled in the rear of the lip, thereby presenting the disadvantages that it is difficult to position the spacer and in the case of the parts before being assembled to the door of the motor vehicle or during assembling work, a slight burr of the lip may cause the spacer to fall off.
In the above-described door construction of the motor vehicle, the aforesaid spacer is coupled in the rear of the lip and the lip is urged against the outer surface of the door glass, thereby presenting the disadvantage that the sliding resistance between the lip and the door glass is increased during the opening or closing of the door glass, to thereby increase the operation load of the window regulator.